The invention relates to a method and an apparatus for treating, and in particular preserving, eggs in their shells on the basis of pasteurization, treating eggs by pasteurization being known in food engineering.
It is known that a poultry egg, which has the most balanced nutritional values after mother's milk, becomes contaminated by secretions from the digestive and urinary system upon passage through the cloaca during laying, and bacteria can be found in the egg and on the eggshell, even in the upper region of the oviduct, as a result of the particular environment or region. The egg and the eggshell are therefore not sterile.
Destruction of microorganisms using heat is a method that has been known for a long time. However, differences in boiling points due to different altitudes above sea level, the use of inconsistent heat, and failure to maintain constant durations mean that only a plurality, or only a portion, of the organisms present in the egg are destroyed. Finally, the known methods or procedures can result in a fundamental change in the egg.
Of the foodstuffs that are subjected to heat treatment, milk is the one that is best known and most used. As is known, milk is not fundamentally changed by the use of pasteurization or the UHT method. Milk and eggs contain microorganisms and viruses that are minimally resistant to heat (such as Salmonella), and those that are heat-resistant due to the environment/region.
Scientific advances have led to descriptions of several diseases that were previously unknown. Advances continue to be made in this research. New techniques and very finely tuned shock methods are being developed for several of the harmful microorganisms and viruses mentioned in these descriptions. In cases in which the pasteurization method does not have an adequate effect, shock methods such as the UHT method are used and recommended.